Referring to FIG. 1, a conventional OLED (organic light-emitting diode) lighting device 1 utilizes includes a housing 11 and at least one lighting module 12 disposed in the housing 11.
Referring further to FIGS. 2 and 3, the lighting module 12 includes a light-transmissible first plate 121, a second plate 122, an electroluminescence element 125 and a plurality of electrodes 126.
The first plate 121 and the second plate 122 are rectangular glass plates. The first plate 121 has an area larger than that of the second plate 122. An encapsulant 129 is disposed about a periphery of the second plate 122 to connect the second plate 122 to the first plate 121, and to cooperate with the second plate 122 and the first plate 121 to define an enclosed space 123. The first plate 121 has a periphery region 124 that surrounds the encapsulant 129 and the enclosed space 123.
The electroluminescence element 125 is an OLED disposed in the enclosed space 123 and generates light that passes through the first plate 121 when supplied with electric power.
Each of the electrodes 126 has an inner portion 127 electrically connected to the electroluminescence element 125, and an outer portion 128 extending from the inner portion 127 and along the periphery region 124 for electrical connection with an external power source (not shown). The plurality of electrodes 126 supply electric power to the electroluminescence element 125 when connected to the external power source.
The purpose of providing the first plate 121 with the periphery region 124 is to hold the outer portion 128 of each of the electrodes 126 while considering the structural symmetry of the lighting module 12. However, a ratio of a lighting area (i.e., area of the electroluminescence element 125) to an overall area of the lighting module 12 (i.e., area of the first plate 121) is thus rather small. Therefore, not only does the lighting module 12 have a relatively inferior effective lighting area, but the overall size of the lighting device 1 is also relatively large due to the presence of the periphery region 124. Moreover, during manufacture or transportation of the lighting device 1, the periphery region 124 is likely to be damaged due to collision with other objects, thereby resulting in a decrease in manufacturing yield.
Therefore, it is required in the art to provide a lighting device with improved effective lighting area and manufacturing yield.